Is It Possible To Preview How Compressor Affects Waveform?

kenTheriot · 04-25-2018, 07:18 AM

What is the best way to visualize what a compressor will do to an audio item?
If I'm only working with a single track - say a voiceover - when I apply normalization to the take in Item Properties window, you can see the waveform normalized immediately.

But if I apply a compressor effect - either on the track or via Take FX in Item Properties, you see no visible change to the waveform.

I've been getting around it by either just Glue-ing the item, or rendering it and checking the "Add rendered items to new track in project box." But it would be a bit more convenient if I could "preview" the affect on the waveform prior to committing to the change via rendering it.

Is that kind of thing even possible?

Thanks!

Lokasenna · 04-25-2018, 07:30 AM

In order to create the preview it would have to render the track anyway...

A visualization would be nice though. I like how a couple of the GVST ones do it, with a scrolling image of the waveform as it plays that shows the compressed signal overlaid on top of the original.

emarsk · 04-25-2018, 07:47 AM

You can put an oscilloscope after the compressor.

By the way, I'm curious: why is it important to see it?

DarkStar · 04-25-2018, 07:48 AM

Get a compressor with a time-graph view:

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That's from MeldaProduction's MDynamicsMB - there is a LOT of choice of what to see.

ashcat_lt · 04-25-2018, 09:15 AM

"Apply Track/Take FX..." and/or "Render to Stems..." is slightly quicker than actually going through the Render dialog. The "Apply..." action is especially handy because it makes a new Take right there under the original waveform where you can compare them pretty easily.

But...

Quote:

Originally Posted by emarsk

By the way, I'm curious: why is it important to see it?

It really doesn't matter what it looks like. What matters is how it sounds.

teniente powell · 04-25-2018, 09:58 AM

Maybe this can help.

https://forum.cockos.com/showthread.php?t=181934

kenTheriot · 04-25-2018, 10:09 AM

Quote:

Originally Posted by emarsk

You can put an oscilloscope after the compressor.

By the way, I'm curious: why is it important to see it?

I never have needed to. But someone asked me and I didn't have an answer, since after all these years, I've never needed to myself :-P. but it did get me wondering why you can see it with Normalize but not compression.

kenTheriot · 04-25-2018, 10:11 AM

Quote:

Originally Posted by ashcat_lt

"Apply Track/Take FX..." and/or "Render to Stems..." is slightly quicker than actually going through the Render dialog. The "Apply..." action is especially handy because it makes a new Take right there under the original waveform where you can compare them pretty easily.

But...

It really doesn't matter what it looks like. What matters is how it sounds.

Cool. Thanks! And I agree. Just want to make sure it isn't going to clip with auto makeup gain.

Xenakios · 04-25-2018, 10:11 AM

Quote:

Originally Posted by kenTheriot

why you can see it with Normalize but not compression.

Because the normalization is a built-in Reaper processing that can be easily visualized since it's just a simple volume change. (Other things like that are take volume envelopes and take realtime reverse playback.)

kenTheriot · 04-25-2018, 10:11 AM

Quote:

Originally Posted by teniente powell

Maybe this can help.

https://forum.cockos.com/showthread.php?t=181934

Very cool. Thanks for that. And thanks to everyone else!!

James HE · 04-25-2018, 10:15 AM

One thing I'll sometimes do when Mastering is to send the output of the track to another track, and "record" to it - giving you the waveform preview. (have to arm the receiving track, set it to record output, make sure it's not monitored or sent to the master, etc, etc.)

A bit cumbersome to set up. It does help if you map some actions to stop recording and discard the recording. But if I'm really wanting to know what the resulting waveform is going to look like, this is a way to go about it.

Magicbuss · 04-25-2018, 11:00 AM

Smexoscope before and after compression- http://bram.smartelectronix.com/plugins.php?id=4

Also GVST Gcomp and Gcomp2 have a waveform view that shows the compressor action.
http://www.gvst.co.uk/downloads.htm

For alot more money Fabfilter has an amazing waveform view that shows the compression action.

kenTheriot · 04-25-2018, 05:16 PM

Thanks for the additional ideas!

kenTheriot · 04-26-2018, 09:35 AM

Quote:

Originally Posted by Xenakios

Because the normalization is a built-in Reaper processing that can be easily visualized since it's just a simple volume change. (Other things like that are take volume envelopes and take realtime reverse playback.)

Makes sense. Thanks.

cjunekim · 05-08-2018, 12:13 AM

There are many ways of visualizing what plugins do to the waveform. My favorite is Skope II at https://sonic.supermaailma.net/plugins You can compare the before and after of waveforms easily.

Put reaeq before the compressor and make its output into 4 channels copying the first two channels into channel 3 and 4.

Put Skope II after the compressor. Adjust the Y scales. If you are using mono track, you can reduce the Y scale of channel 2 and 4 to zero. Now adjust the display align to separate the channels as you want.

Or you may use the recently added gain reduction scope jsfx.

Quote:

Originally Posted by kenTheriot

What is the best way to visualize what a compressor will do to an audio item?
If I'm only working with a single track - say a voiceover - when I apply normalization to the take in Item Properties window, you can see the waveform normalized immediately.

But if I apply a compressor effect - either on the track or via Take FX in Item Properties, you see no visible change to the waveform.

I've been getting around it by either just Glue-ing the item, or rendering it and checking the "Add rendered items to new track in project box." But it would be a bit more convenient if I could "preview" the affect on the waveform prior to committing to the change via rendering it.

Is that kind of thing even possible?

Thanks!

kenTheriot · 05-08-2018, 06:02 AM

Quote:

Originally Posted by cjunekim

There are many ways of visualizing what plugins do to the waveform. My favorite is Skope II at https://sonic.supermaailma.net/plugins You can compare the before and after of waveforms easily.

Put reaeq before the compressor and make its output into 4 channels copying the first two channels into channel 3 and 4.

Put Skope II after the compressor. Adjust the Y scales. If you are using mono track, you can reduce the Y scale of channel 2 and 4 to zero. Now adjust the display align to separate the channels as you want.

Or you may use the recently added gain reduction scope jsfx.

That's really interesting. I'll definitely be checking that out. Thanks!